Lucas Irwin surprised his parents last Christmas with his 130-pound weight loss and caught their reaction on video, which is now going viral, reported the New York Daily News on Jan. 8.

Imgur by Lucas Irwin

At 300-pounds, the 25-year-old Irwin made the commitment to lose weight in 2013. He did not share that promise to himself with his parents.

Irwin reportedly only goes home twice a year, and made up an excuse to not go home over the summer just "so they wouldn't see me".

Irwin lost 130-pounds through a strict 1350 calorie per day diet and exercise. According to Irwin, no foods were off limit, but he "survived mostly on tuna salad, chicken with salsa, frozen vegetables, beans and rice, turkey/roast beef sandwiches, spinach and eggs."

He also shared with the Reddit community that once he lost 100-pounds, he started walking five miles to work for about two months, weather permitting.

Said Irwin, "I lost 95 percent of the weight just through changing my diet. I didn't exercise at all until maybe seven or eight months in."

Irwin now weighs in at 170-pounds and surprised his parents over the holidays with his dramatic weight loss. Irwin admitted that he was nervous to see them. "I was shaking and … it was very surreal."

"All of the sudden, down the stairs he came, and he looked just fantastic. I was more stunned than anything else. But inside, I was just beaming. I was just ... I was over the moon," said Irwin's father Jeff Irwin.

Irwin caught his parents' shock and happy disbelief on a video that has now gone viral online. Irwin said that his weight loss goal isn't completed yet. According to Irwin, he would like to lose another 20-pounds.